RFC 1115 states that the DEK being encrypted is padded with pseudorandom,
non-zero bytes. I interpret this as meaning each Key-Info field is padded
with a different pseudorandom byte string, so the block being encrypted
under RSA is different for each recipient.
PKCS #1 states this a little more strongly: "... it is recommended that
the pseudorandom octets be generated independently for each encryption
process, especially if the same data is input to more than one encryption
process."
Regards,
Rich